For a chassis to be really flexible in it's use like getting under NRLH Heavy class with the right accessories and still weighing 26-28lbs for PRS the hard part isn't top end weight right now. It's bottom end. Right now my favorite chassis is the ATX AICS chassis. I had a CRB Comp Contour barrel, NF 7x35, braked suppressor, CkyePod, and some gadgets on it for PRS. With three sets of side weights and all the internal foreend weights, it was at 26.5lbs. I just pulled all the weights out of it, took all the gadgets off, and screwed on a 26" Heavy Palma .223 barrel with a TBAC U9 to use the rifle as a Pdog gun on the side after I tag out antelope hunting this weekend. I would like to be able to throw on a 24" CF barrel with a Scythe-Ti/ RX brake and use it for some NRLH matches in late winter but I don't think I'll make weight without going to a lighter scope or bipod. Neither of which I want to do.
Do some digging around on manufacturers websites and check out base weights. You'll also have to have all your other gun parts weight-itemized for context. But if you don't actually care about making a certain base weight then it doesn't really matter. You can make almost any gun using all the usual suspects of top chassis heavy enough. If you're not going to be reconfiguring the rifle throughout the year then it's an unnecessary question.
I have an XLR Envy with the PRS comp kit. My only complaint about it is the side weights aren't that heavy. I think they're 6oz each. Kind of small and seem designed for looks. The ATX weights are 8oz each and the square blockiness of them create a Baker wing type of effect on a bag. When you add a set of side weights you know you're adding a full pound to the gun.
